While the 2017 Audi A4 is an entirely new vehicle, its shape isn't strikingly different from the car it replaces.

The innovations come largely in a broad suite of comfort and electronic assistance features that will take the car into the 2020s.

Now, however, Audi has decided that the A4 won't be offered in the U.S. with the 2.0-liter TDI diesel engine that was expected to be its most fuel-efficient model.

DON'T MISS: How Can VW, Audi Dealers Still Sell Used TDI Diesel Vehicles?

According to industry trade journal Automotive News, the news came from Audi of America president Scott Keogh at an A4 drive event in California.

Keogh said that the decision reflected lower demand for diesel variants of Audi's sedans versus those for its crossover utility vehicles.

2014 Audi A7 TDI

2014 Audi A7 TDI

He denied that the decision was a result of the ongoing Volkswagen diesel-emission scandal, now ending its sixth month with little resolution in sight.

Instead, Keogh said, the marketplace—in the form of Audi dealers and buyers—had indicated that diesel sedans would not prove to be all that popular.

ALSO SEE: BMW Admits VW Emission Scandal Hurts All Diesel Sales In U.S.

In the first six months of 2015, before the scandal erupted in September, TDI diesel versions accounted for only 6 to 8 percent of Audi's A6 and A8 sedans and A7 hatchbacks.

That compares, Keogh said, to 12 percent of Q5 compact SUV sales (and more than one in five of the low-volume Q7 large crossover).

2014 Audi Q5 TDI, Catskill Mountains, Oct 2013

2014 Audi Q5 TDI, Catskill Mountains, Oct 2013

The TDI versions of all five models are presently off the market under a "stop-sale" order applying to new and certified used models of all Audi diesel vehicles.

The decision to scrap the A4 TDI marks a big change of strategy for Audi, which decided in early 2013 to offer the latest 2.0-liter diesel engine in the all-new sport sedan, one of its best-selling vehicles.

But Audi's experience with the diesel versions of the A6, A7, and A8 indicated, Keogh said, "there was not significant market demand for the TDI sedans we [already] had in the marketplace."

CHECK OUT: Diesels Still Needed For Truck Fuel Economy Despite VW Scandal: Advocate

VW's luxury brand will continue offering the diesel versions of its current sedans, whenever the EPA certifies the 2016 and later models for sale in the U.S.

The decision on whether to continue with diesel sedans won't be made until that range comes up for redesign a few years hence.

Meanwhile, prospects for diesel pickup trucks and SUVs remain strong, according to Diesel Technology Forum executive director Allen Schaeffer.

2017 Audi A4

2017 Audi A4

He said that while the fate of diesel passenger cars such as those offered by Volkswagen was yet to be determined, larger SUVs and pickup trucks continue to see strong demand for diesel versions.

Schaeffer made the comments to an audience of automotive journalists yesterday at a presentation sponsored by the International Motor Press Association in New York City.


Follow GreenCarReports on Facebook and Twitter.